Field of the Invention
The subject invention relates to a device for withdrawing a fluid specimen from a patient and subsequently dispensing the collected fluid into a collection container. More particularly, this invention relates to a safety syringe for withdrawing a fluid specimen, such as blood, from a patient, retracting the needle element of the device into the housing of the device, and subsequently dispensing the collected fluid into a separate collection container.
Description of Related Art
Hypodermic syringes are widely used in the medical arts for withdrawing fluid samples from a patient. Generally, hypodermic syringes have a metal needle that has a sharpened distal point for penetrating a patient's skin that is either fixedly or removably attached to a housing. With the recognition of fluid borne diseases that are transmitted by bodily fluids, and greater sensitivity of the need to protect healthcare workers from inadvertent contact with previously used needles (commonly referred to as “sharps”), as well as the need to reduce criminal misuse of improperly disposed needles and syringes, syringes that include provisions to prevent reuse and reduce exposure to healthcare workers have been developed.
A variety of shielding mechanisms have also been developed to reduce the incidence of inadvertent exposure of healthcare workers to sharps, however, most of these devices can be compromised by an individual determined to obtain and misuse a hypodermic syringe after its intended use. As a result, further developments in the art of hypodermic syringes have resulted in the advent of hypodermic syringes having needles that withdraw into the body of the syringe once their intended use is completed.
Most of the conventional syringe assemblies in which the needle is withdrawn into the body of the syringe require manufacture and assembly of parts with tight tolerance requirements. Many of the designs depend upon a careful application of forces by the practitioner to draw and/or expel fluids from the syringe. In these assemblies, deviance from the tight tolerances of the multiple components of the device during manufacture and assembly may result in premature activation of the retraction function of the syringe. In addition, conventional syringe assemblies, including a retraction aspect, have been developed for the limited purpose of injecting a medication into a patient, and do not address the need for a syringe used for bodily fluid collection having a retraction element.
Current conventional syringes are considered by users to be virtually fault-free and reliable. They are used for a variety of different procedures involving both “one-shot” fill and inject procedures, as well as more complex mixing, measuring, and delivery functions. In order for a retractable syringe to displace these functional, utilitarian, and reliable conventional syringes, the new retractable syringe should not interfere with current practices, should be cost-effective, and must be substantially reliable. Current conventional syringes are often manufactured at rates of several hundred per minute and their cost is generally not a significant factor in their usage. One skilled in the art of high volume manufacturing recognizes that assembling hundreds of millions of complex retraction syringes having retraction elements contained in a small space, for example on the order of a one-quarter inch diameter bore, is a daunting task.
Accordingly, a need exists for a retractable syringe that is suitable for use as a bodily fluid collection device for subsequent transfer to a collection container. A need further exists for a retractable syringe that is capable of being manufactured at high volumes, and is sufficiently reliable in use when produced at high volume. Such a device is disclosed herein below.